Artigos Técnicos e Apresentações

Aqui você encontrará apresentações realizadas nas Conferências de Usuários COMSOL de todo o mundo. As apresentações englobam pesquisas e produtos inovadores feitas por engenheiros e cientistas usando o COMSOL Multiphysics. Os tópicos abramgem uma grande gama de indústrias e aplicações, como elétrica, mecânica, escoamento e química. Use a função de busca "Quick Search" para encontrar apresentações na sua área de interesse.

Numerical Aspects of the Implementation of Artificial Boundary Conditions for Laminar Fluid-Structure Interactions

C. Boeckle[1], P. Wittwer[1]
[1]University of Geneva, Geneva, Switzerland

We discuss the implementation of artificial boundary conditions for stationary Navier-Stokes flows past bodies in the half-plane, for a range of low Reynolds numbers. When truncating the half-plane to a finite domain for numerical purposes, artificial boundaries appear. We present an explicit Dirichlet condition for the velocity at these boundaries in terms of an asymptotic expansion for the ...

Piezoelectric Buzzer Optimization for Micropumps

A. Garcia[1], A. Marcus[1], F. Tejo[1], C. Precker[1], C. Moreira[2]
[1]Universidade Federal de Campina Grande, Campina Grande, PB, Brazil
[2]Instituto Federal de Alagoas, Maceio, AL, Brazil

Piezoelectric buzzers are low cost devices which can be used successfully as actuators in diaphragm-based micro-pumps. The buzzers are piezoelectric wafers (lead-zirconate-titanate-PZT) that are glued on a brass membrane and they are available within different sizes and thicknesses. For the best performance of a diaphragm pump, it is necessary to have a large displacement of the membrane. This ...

Establishing Absorbed Dose Thresholds for Nonlinearities in Water Calorimetry

R.E. Tosh[1], H. Chen-Mayer[1]
[1]National Institute of Standards and Technology, Gaithersburg, MD, USA

The technique of water calorimetry for primary-standard dosimetry of radiotherapy-level ionizing radiation is well established at national metrology institutes around the world, where such a direct realization of absorbed dose establishes the basis for calibrating instruments used for dosimetry in medical settings. The typical calorimeter system uses miniature thermistor beads to measure ...

Exergy Analysis of a Water Heat Storage Tank

F. Dammel[1], J. Winterling[1], K. J. Langeheinecke[2], P. Stephan[3]
[1]Institute of Technical Thermodynamics, Technische Universität Darmstadt, Germany
[2]IAV, Gifhorn, Germany
[3]Institute of Technical Thermodynamics/Center of Smart Interfaces, Technische Universität, Darmstadt, Germany

A combined heat and power (CHP) plant generates both electricity and useful heat. A heat storage tank enables a decoupling of electricity and heat delivery. In this study a cylindrical hot water storage tank is considered. Charging, holding time and discharging are numerically simulated applying COMSOL Multiphysics 4.2. The performance of the heat storage is evaluated by an exergy analysis. ...

Accelerating R&D with COMSOL: A Personal Account

Erik Birgersson[1]

[1]Department of Chemical and Biomolecular Engineering, National University of Singapore, Singapore, Singapore

This presentation gives an account of how COMSOL Multiphysics® software has helped to accelerate research and development. It has been used to simulate energy systems such as fuel cells, biomedical systems such as hydrogels and human skin, and monolithic catalytic converters. Each of these systems requires a mathematical model that can accurately represent the relevant physics, and which can be ...

Improvements on Liquid Cyclotron Target Loading/Unloading System Using COMSOL Multiphysics®

F. Alrumayan[1], A. Alghaith[1], J. Schneider, [1], M. Ahmed [1], M. Al-Qahtani[1]
[1]King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia

A 3D model was developed using COMSOL Multiphysics® to study the flow dynamics of the water inside the geometry of the [13N] Ammonia target for medical application . The image attached shows a 3D model of the target. A significant improvement was noted after modifying the geometry as suggested by the model and delivery time of radioactive solution was dramatically reduced. Water and aluminum ...

Biological Effects and Therapeutic Applications of Electromagnetic Radiations

A. Singh[1], S. Maini[1], and M. Anupma[1]
[1] Department of Electrical & Instrumentation Engineering, Sant Longowal Institute of Engineering and Technology , Longowal (Deemed University), Punjab, India

The electromagnetic fields have a great influence on the behavior of all the living systems. The human body itself is a source of naturally generated electric and magnetic fields. When external signals of comparable strength flows through the human body; the nature of changes that such signals could induce in natural electrochemical processes and voltage is a subject of interest and of ...

Local Electroporation of Single Adherent Cells by Micro-Structured Needle Electrodes

K. K. Sriperumbudur[1], P. J. Koester[1], M. Stubbe[1], C. Tautorat[1], J. Held[2], W. Baumann[1], and J. Gimsa[1]
[1] University of Rostock, Chair of Biophysics, Gertrudenstr. 11a, 18057 Rostock, Germany
[2] Microsystem Material Laboratory, Department of Microsystems Engineering (IMTEK), University of Freiburg, Germany

In spite of its low throughput, Patch-Clamp is the established method for intracellular measurements of the transmembrane potential. To address this problem, we have developed new biosensor-chips with micro-structured needle electrodes (MNEs). MNE-penetration of single cells growing on the MNE-tips leads to a situation comparable to the whole-cell mode in classical Patch Clamp. MNE-penetration ...

Stress Driven Remodeling of Living Tissues

Nardinocchi, P.1, Teresi, L.2
1 Università degli Studi di Roma ”La Sapienza”
2 Università degli Studi Roma Tre

The present study addresses the evolution of the smooth muscles of which blood-vessel walls are composed, in the framework of a continuum model concerning material remodeling presented in [1]. By material remodeling we mean all those microscopic processes whose effects emerge at macroscopic level as evolution of the relaxed state of a body, and, as consequence, of its actual configuration. We ...

Numerical Simulation of Heart Valve Motion and Fluid Structure Interaction

Tijerino Monge, T., Carmona Infante, V.
Costa Rica

This model studies a portion of the vascular system of a normal person, in particular the left ventricle and the mitral valve of the heart. The flowing blood applies pressure to the ventricle before, after and specially during the contraction process of the heart, thereby deforming the structure.

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